Several classes of haloalkylsulfonamido-substituted aromatic compounds have been known heretofore, as have certain uses for these compounds. Thus, U.S. Pat. No. 3,639,474 discloses trifluoromethanesulfonanilides, including such compounds with trifluoromethyl, methylthio, methylsulfinyl and methylsulfonyl substituents, to be useful as herbicides. French Pat. No. 1,188,591 includes disclosures of two classes of compounds, i.e. haloalkylsulfonanilides and haloalkylsulfonamidodiphenyl compounds in which the rings are bonded directly or are linked by various groups including sulfonyl, sulfinyl and thio groups. The areas of utility disclosed by the French patent include activity against textile material parasites as well as antibacterial and anti-mildew activity. Herbicidal activity is not disclosed in that patent however. British Patent 971,219 discloses alkanesulfonanilides containing both chlorine and nitro ring substituents to have herbicidal activity.
The present invention provides a limited class of novel compounds which contain a non-fluorinated methanesulfonamido group and which have a unique and particularly valuable spectrum of activity. They are especially effective in controlling established rhizomatous Johnson Grass (Sorghum halepense (L. Pers.)). This is of significance since while seedling Johnson Grass is susceptible to several commercial herbicides, rhizomatous Johnson Grass is not controlled effectively at application rates of such materials that are tolerated by crops. It is unexpected to find such effective control of established rhizomatous Johnson Grass in the compounds of the invention. The compounds of the invention have also been found to be particularly effective in controlling nutsedge (for example Cyperus esculentus) species.